src/Core/Worker.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Core;
  23
  24 use Friendica\Core;
  25 use Friendica\Database\DBA;
  26 use Friendica\DI;
  27 use Friendica\Model\Process;
  28 use Friendica\Util\DateTimeFormat;
  29 use Friendica\Util\Network;
  30
  31 /**
  32  * Contains the class for the worker background job processing
  33  */
  34 class Worker
  35 {
  36         const STATE_STARTUP    = 1; // Worker is in startup. This takes most time.
  37         const STATE_LONG_LOOP  = 2; // Worker is processing the whole - long - loop.
  38         const STATE_REFETCH    = 3; // Worker had refetched jobs in the execution loop.
  39         const STATE_SHORT_LOOP = 4; // Worker is processing preassigned jobs, thus saving much time.
  40
  41         const FAST_COMMANDS = ['APDelivery', 'Delivery', 'CreateShadowEntry'];
  42
  43
  44         private static $up_start;
  45         private static $db_duration = 0;
  46         private static $db_duration_count = 0;
  47         private static $db_duration_write = 0;
  48         private static $db_duration_stat = 0;
  49         private static $lock_duration = 0;
  50         private static $last_update;
  51         private static $state;
  52
  53         /**
  54          * Processes the tasks that are in the workerqueue table
  55          *
  56          * @param boolean $run_cron Should the cron processes be executed?
  57          * @return void
  58          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  59          */
  60         public static function processQueue($run_cron = true)
  61         {
  62                 // Ensure that all "strtotime" operations do run timezone independent
  63                 date_default_timezone_set('UTC');
  64
  65                 self::$up_start = microtime(true);
  66
  67                 // At first check the maximum load. We shouldn't continue with a high load
  68                 if (DI::process()->isMaxLoadReached()) {
  69                         Logger::log('Pre check: maximum load reached, quitting.', Logger::DEBUG);
  70                         return;
  71                 }
  72
  73                 // We now start the process. This is done after the load check since this could increase the load.
  74                 self::startProcess();
  75
  76                 // Kill stale processes every 5 minutes
  77                 $last_cleanup = DI::config()->get('system', 'worker_last_cleaned', 0);
  78                 if (time() > ($last_cleanup + 300)) {
  79                         DI::config()->set('system', 'worker_last_cleaned', time());
  80                         self::killStaleWorkers();
  81                 }
  82
  83                 // Count active workers and compare them with a maximum value that depends on the load
  84                 if (self::tooMuchWorkers()) {
  85                         Logger::log('Pre check: Active worker limit reached, quitting.', Logger::DEBUG);
  86                         return;
  87                 }
  88
  89                 // Do we have too few memory?
  90                 if (DI::process()->isMinMemoryReached()) {
  91                         Logger::log('Pre check: Memory limit reached, quitting.', Logger::DEBUG);
  92                         return;
  93                 }
  94
  95                 // Possibly there are too much database connections
  96                 if (self::maxConnectionsReached()) {
  97                         Logger::log('Pre check: maximum connections reached, quitting.', Logger::DEBUG);
  98                         return;
  99                 }
 100
 101                 // Possibly there are too much database processes that block the system
 102                 if (DI::process()->isMaxProcessesReached()) {
 103                         Logger::log('Pre check: maximum processes reached, quitting.', Logger::DEBUG);
 104                         return;
 105                 }
 106
 107                 // Now we start additional cron processes if we should do so
 108                 if ($run_cron) {
 109                         self::runCron();
 110                 }
 111
 112                 $starttime = time();
 113                 self::$state = self::STATE_STARTUP;
 114
 115                 // We fetch the next queue entry that is about to be executed
 116                 while ($r = self::workerProcess()) {
 117                         $refetched = false;
 118                         foreach ($r as $entry) {
 119                                 // Assure that the priority is an integer value
 120                                 $entry['priority'] = (int)$entry['priority'];
 121
 122                                 // The work will be done
 123                                 if (!self::execute($entry)) {
 124                                         Logger::log('Process execution failed, quitting.', Logger::DEBUG);
 125                                         return;
 126                                 }
 127
 128                                 // Trying to fetch new processes - but only once when successful
 129                                 if (!$refetched && DI::lock()->acquire('worker_process', 0)) {
 130                                         self::findWorkerProcesses();
 131                                         DI::lock()->release('worker_process');
 132                                         self::$state = self::STATE_REFETCH;
 133                                         $refetched = true;
 134                                 } else {
 135                                         self::$state = self::STATE_SHORT_LOOP;
 136                                 }
 137                         }
 138
 139                         // To avoid the quitting of multiple workers only one worker at a time will execute the check
 140                         if (!self::getWaitingJobForPID()) {
 141                                 self::$state = self::STATE_LONG_LOOP;
 142
 143                                 if (DI::lock()->acquire('worker', 0)) {
 144                                 // Count active workers and compare them with a maximum value that depends on the load
 145                                         if (self::tooMuchWorkers()) {
 146                                                 Logger::log('Active worker limit reached, quitting.', Logger::DEBUG);
 147                                                 DI::lock()->release('worker');
 148                                                 return;
 149                                         }
 150
 151                                         // Check free memory
 152                                         if (DI::process()->isMinMemoryReached()) {
 153                                                 Logger::log('Memory limit reached, quitting.', Logger::DEBUG);
 154                                                 DI::lock()->release('worker');
 155                                                 return;
 156                                         }
 157                                         DI::lock()->release('worker');
 158                                 }
 159                         }
 160
 161                         // Quit the worker once every cron interval
 162                         if (time() > ($starttime + (DI::config()->get('system', 'cron_interval') * 60))) {
 163                                 Logger::info('Process lifetime reached, respawning.');
 164                                 self::spawnWorker();
 165                                 return;
 166                         }
 167                 }
 168
 169                 // Cleaning up. Possibly not needed, but it doesn't harm anything.
 170                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
 171                         self::IPCSetJobState(false);
 172                 }
 173                 Logger::log("Couldn't select a workerqueue entry, quitting process " . getmypid() . ".", Logger::DEBUG);
 174         }
 175
 176         /**
 177          * Check if non executed tasks do exist in the worker queue
 178          *
 179          * @return boolean Returns "true" if tasks are existing
 180          * @throws \Exception
 181          */
 182         private static function entriesExists()
 183         {
 184                 $stamp = (float)microtime(true);
 185                 $exists = DBA::exists('workerqueue', ["NOT `done` AND `pid` = 0 AND `next_try` < ?", DateTimeFormat::utcNow()]);
 186                 self::$db_duration += (microtime(true) - $stamp);
 187                 return $exists;
 188         }
 189
 190         /**
 191          * Returns the number of deferred entries in the worker queue
 192          *
 193          * @return integer Number of deferred entries in the worker queue
 194          * @throws \Exception
 195          */
 196         private static function deferredEntries()
 197         {
 198                 $stamp = (float)microtime(true);
 199                 $count = DBA::count('workerqueue', ["NOT `done` AND `pid` = 0 AND `retrial` > ?", 0]);
 200                 self::$db_duration += (microtime(true) - $stamp);
 201                 self::$db_duration_count += (microtime(true) - $stamp);
 202                 return $count;
 203         }
 204
 205         /**
 206          * Returns the number of non executed entries in the worker queue
 207          *
 208          * @return integer Number of non executed entries in the worker queue
 209          * @throws \Exception
 210          */
 211         private static function totalEntries()
 212         {
 213                 $stamp = (float)microtime(true);
 214                 $count = DBA::count('workerqueue', ['done' => false, 'pid' => 0]);
 215                 self::$db_duration += (microtime(true) - $stamp);
 216                 self::$db_duration_count += (microtime(true) - $stamp);
 217                 return $count;
 218         }
 219
 220         /**
 221          * Returns the highest priority in the worker queue that isn't executed
 222          *
 223          * @return integer Number of active worker processes
 224          * @throws \Exception
 225          */
 226         private static function highestPriority()
 227         {
 228                 $stamp = (float)microtime(true);
 229                 $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 230                 $workerqueue = DBA::selectFirst('workerqueue', ['priority'], $condition, ['order' => ['priority']]);
 231                 self::$db_duration += (microtime(true) - $stamp);
 232                 if (DBA::isResult($workerqueue)) {
 233                         return $workerqueue["priority"];
 234                 } else {
 235                         return 0;
 236                 }
 237         }
 238
 239         /**
 240          * Returns if a process with the given priority is running
 241          *
 242          * @param integer $priority The priority that should be checked
 243          *
 244          * @return integer Is there a process running with that priority?
 245          * @throws \Exception
 246          */
 247         private static function processWithPriorityActive($priority)
 248         {
 249                 $condition = ["`priority` <= ? AND `pid` != 0 AND NOT `done`", $priority];
 250                 return DBA::exists('workerqueue', $condition);
 251         }
 252
 253         /**
 254          * Execute a worker entry
 255          *
 256          * @param array $queue Workerqueue entry
 257          *
 258          * @return boolean "true" if further processing should be stopped
 259          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 260          */
 261         public static function execute($queue)
 262         {
 263                 $mypid = getmypid();
 264
 265                 // Quit when in maintenance
 266                 if (DI::config()->get('system', 'maintenance', false, true)) {
 267                         Logger::log("Maintenance mode - quit process ".$mypid, Logger::DEBUG);
 268                         return false;
 269                 }
 270
 271                 // Constantly check the number of parallel database processes
 272                 if (DI::process()->isMaxProcessesReached()) {
 273                         Logger::log("Max processes reached for process ".$mypid, Logger::DEBUG);
 274                         return false;
 275                 }
 276
 277                 // Constantly check the number of available database connections to let the frontend be accessible at any time
 278                 if (self::maxConnectionsReached()) {
 279                         Logger::log("Max connection reached for process ".$mypid, Logger::DEBUG);
 280                         return false;
 281                 }
 282
 283                 $argv = json_decode($queue["parameter"], true);
 284
 285                 // Check for existance and validity of the include file
 286                 $include = $argv[0];
 287
 288                 if (method_exists(sprintf('Friendica\Worker\%s', $include), 'execute')) {
 289                         // We constantly update the "executed" date every minute to avoid being killed too soon
 290                         if (!isset(self::$last_update)) {
 291                                 self::$last_update = strtotime($queue["executed"]);
 292                         }
 293
 294                         $age = (time() - self::$last_update) / 60;
 295                         self::$last_update = time();
 296
 297                         if ($age > 1) {
 298                                 $stamp = (float)microtime(true);
 299                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 300                                 self::$db_duration += (microtime(true) - $stamp);
 301                                 self::$db_duration_write += (microtime(true) - $stamp);
 302                         }
 303
 304                         array_shift($argv);
 305
 306                         self::execFunction($queue, $include, $argv, true);
 307
 308                         $stamp = (float)microtime(true);
 309                         $condition = ["`id` = ? AND `next_try` < ?", $queue['id'], DateTimeFormat::utcNow()];
 310                         if (DBA::update('workerqueue', ['done' => true], $condition)) {
 311                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 312                         }
 313                         self::$db_duration = (microtime(true) - $stamp);
 314                         self::$db_duration_write += (microtime(true) - $stamp);
 315
 316                         return true;
 317                 }
 318
 319                 // The script could be provided as full path or only with the function name
 320                 if ($include == basename($include)) {
 321                         $include = "include/".$include.".php";
 322                 }
 323
 324                 if (!validate_include($include)) {
 325                         Logger::log("Include file ".$argv[0]." is not valid!");
 326                         $stamp = (float)microtime(true);
 327                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 328                         self::$db_duration = (microtime(true) - $stamp);
 329                         self::$db_duration_write += (microtime(true) - $stamp);
 330                         return true;
 331                 }
 332
 333                 require_once $include;
 334
 335                 $funcname = str_replace(".php", "", basename($argv[0]))."_run";
 336
 337                 if (function_exists($funcname)) {
 338                         // We constantly update the "executed" date every minute to avoid being killed too soon
 339                         if (!isset(self::$last_update)) {
 340                                 self::$last_update = strtotime($queue["executed"]);
 341                         }
 342
 343                         $age = (time() - self::$last_update) / 60;
 344                         self::$last_update = time();
 345
 346                         if ($age > 1) {
 347                                 $stamp = (float)microtime(true);
 348                                 DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow()], ['pid' => $mypid, 'done' => false]);
 349                                 self::$db_duration += (microtime(true) - $stamp);
 350                                 self::$db_duration_write += (microtime(true) - $stamp);
 351                         }
 352
 353                         self::execFunction($queue, $funcname, $argv, false);
 354
 355                         $stamp = (float)microtime(true);
 356                         if (DBA::update('workerqueue', ['done' => true], ['id' => $queue["id"]])) {
 357                                 DI::config()->set('system', 'last_worker_execution', DateTimeFormat::utcNow());
 358                         }
 359                         self::$db_duration = (microtime(true) - $stamp);
 360                         self::$db_duration_write += (microtime(true) - $stamp);
 361                 } else {
 362                         Logger::log("Function ".$funcname." does not exist");
 363                         $stamp = (float)microtime(true);
 364                         DBA::delete('workerqueue', ['id' => $queue["id"]]);
 365                         self::$db_duration = (microtime(true) - $stamp);
 366                         self::$db_duration_write += (microtime(true) - $stamp);
 367                 }
 368
 369                 return true;
 370         }
 371
 372         /**
 373          * Execute a function from the queue
 374          *
 375          * @param array   $queue       Workerqueue entry
 376          * @param string  $funcname    name of the function
 377          * @param array   $argv        Array of values to be passed to the function
 378          * @param boolean $method_call boolean
 379          * @return void
 380          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 381          */
 382         private static function execFunction($queue, $funcname, $argv, $method_call)
 383         {
 384                 $a = DI::app();
 385
 386                 $argc = count($argv);
 387
 388                 Logger::enableWorker($funcname);
 389
 390                 Logger::info("Process start.", ['priority' => $queue["priority"], 'id' => $queue["id"]]);
 391
 392                 $stamp = (float)microtime(true);
 393
 394                 // We use the callstack here to analyze the performance of executed worker entries.
 395                 // For this reason the variables have to be initialized.
 396                 DI::profiler()->reset();
 397
 398                 $a->queue = $queue;
 399
 400                 $up_duration = microtime(true) - self::$up_start;
 401
 402                 // Reset global data to avoid interferences
 403                 unset($_SESSION);
 404
 405                 // Set the workerLogger as new default logger
 406                 if ($method_call) {
 407                         call_user_func_array(sprintf('Friendica\Worker\%s::execute', $funcname), $argv);
 408                 } else {
 409                         $funcname($argv, $argc);
 410                 }
 411
 412                 Logger::disableWorker();
 413
 414                 unset($a->queue);
 415
 416                 $duration = (microtime(true) - $stamp);
 417
 418                 /* With these values we can analyze how effective the worker is.
 419                  * The database and rest time should be low since this is the unproductive time.
 420                  * The execution time is the productive time.
 421                  * By changing parameters like the maximum number of workers we can check the effectivness.
 422                 */
 423                 $dbtotal = round(self::$db_duration, 2);
 424                 $dbread  = round(self::$db_duration - (self::$db_duration_count + self::$db_duration_write + self::$db_duration_stat), 2);
 425                 $dbcount = round(self::$db_duration_count, 2);
 426                 $dbstat  = round(self::$db_duration_stat, 2);
 427                 $dbwrite = round(self::$db_duration_write, 2);
 428                 $dblock  = round(self::$lock_duration, 2);
 429                 $rest    = round(max(0, $up_duration - (self::$db_duration + self::$lock_duration)), 2);
 430                 $exec    = round($duration, 2);
 431
 432                 Logger::info('Performance:', ['state' => self::$state, 'count' => $dbcount, 'stat' => $dbstat, 'write' => $dbwrite, 'lock' => $dblock, 'total' => $dbtotal, 'rest' => $rest, 'exec' => $exec]);
 433
 434                 self::$up_start = microtime(true);
 435                 self::$db_duration = 0;
 436                 self::$db_duration_count = 0;
 437                 self::$db_duration_stat = 0;
 438                 self::$db_duration_write = 0;
 439                 self::$lock_duration = 0;
 440
 441                 if ($duration > 3600) {
 442                         Logger::info('Longer than 1 hour.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 443                 } elseif ($duration > 600) {
 444                         Logger::info('Longer than 10 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 445                 } elseif ($duration > 300) {
 446                         Logger::info('Longer than 5 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 447                 } elseif ($duration > 120) {
 448                         Logger::info('Longer than 2 minutes.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration/60, 3)]);
 449                 }
 450
 451                 Logger::info('Process done.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'duration' => round($duration, 3)]);
 452
 453                 DI::profiler()->saveLog(DI::logger(), "ID " . $queue["id"] . ": " . $funcname);
 454
 455                 $cooldown = DI::config()->get("system", "worker_cooldown", 0);
 456
 457                 if ($cooldown > 0) {
 458                         Logger::info('Cooldown.', ['priority' => $queue["priority"], 'id' => $queue["id"], 'cooldown' => $cooldown]);
 459                         sleep($cooldown);
 460                 }
 461         }
 462
 463         /**
 464          * Checks if the number of database connections has reached a critical limit.
 465          *
 466          * @return bool Are more than 3/4 of the maximum connections used?
 467          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 468          */
 469         private static function maxConnectionsReached()
 470         {
 471                 // Fetch the max value from the config. This is needed when the system cannot detect the correct value by itself.
 472                 $max = DI::config()->get("system", "max_connections");
 473
 474                 // Fetch the percentage level where the worker will get active
 475                 $maxlevel = DI::config()->get("system", "max_connections_level", 75);
 476
 477                 if ($max == 0) {
 478                         // the maximum number of possible user connections can be a system variable
 479                         $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_user_connections'");
 480                         if (DBA::isResult($r)) {
 481                                 $max = $r["Value"];
 482                         }
 483                         // Or it can be granted. This overrides the system variable
 484                         $stamp = (float)microtime(true);
 485                         $r = DBA::p('SHOW GRANTS');
 486                         self::$db_duration += (microtime(true) - $stamp);
 487                         while ($grants = DBA::fetch($r)) {
 488                                 $grant = array_pop($grants);
 489                                 if (stristr($grant, "GRANT USAGE ON")) {
 490                                         if (preg_match("/WITH MAX_USER_CONNECTIONS (\d*)/", $grant, $match)) {
 491                                                 $max = $match[1];
 492                                         }
 493                                 }
 494                         }
 495                         DBA::close($r);
 496                 }
 497
 498                 // If $max is set we will use the processlist to determine the current number of connections
 499                 // The processlist only shows entries of the current user
 500                 if ($max != 0) {
 501                         $stamp = (float)microtime(true);
 502                         $r = DBA::p('SHOW PROCESSLIST');
 503                         self::$db_duration += (microtime(true) - $stamp);
 504                         $used = DBA::numRows($r);
 505                         DBA::close($r);
 506
 507                         Logger::log("Connection usage (user values): ".$used."/".$max, Logger::DEBUG);
 508
 509                         $level = ($used / $max) * 100;
 510
 511                         if ($level >= $maxlevel) {
 512                                 Logger::log("Maximum level (".$maxlevel."%) of user connections reached: ".$used."/".$max);
 513                                 return true;
 514                         }
 515                 }
 516
 517                 // We will now check for the system values.
 518                 // This limit could be reached although the user limits are fine.
 519                 $r = DBA::fetchFirst("SHOW VARIABLES WHERE `variable_name` = 'max_connections'");
 520                 if (!DBA::isResult($r)) {
 521                         return false;
 522                 }
 523                 $max = intval($r["Value"]);
 524                 if ($max == 0) {
 525                         return false;
 526                 }
 527                 $r = DBA::fetchFirst("SHOW STATUS WHERE `variable_name` = 'Threads_connected'");
 528                 if (!DBA::isResult($r)) {
 529                         return false;
 530                 }
 531                 $used = intval($r["Value"]);
 532                 if ($used == 0) {
 533                         return false;
 534                 }
 535                 Logger::log("Connection usage (system values): ".$used."/".$max, Logger::DEBUG);
 536
 537                 $level = $used / $max * 100;
 538
 539                 if ($level < $maxlevel) {
 540                         return false;
 541                 }
 542                 Logger::log("Maximum level (".$level."%) of system connections reached: ".$used."/".$max);
 543                 return true;
 544         }
 545
 546         /**
 547          * fix the queue entry if the worker process died
 548          *
 549          * @return void
 550          * @throws \Exception
 551          */
 552         private static function killStaleWorkers()
 553         {
 554                 $stamp = (float)microtime(true);
 555                 $entries = DBA::select(
 556                         'workerqueue',
 557                         ['id', 'pid', 'executed', 'priority', 'parameter'],
 558                         ['NOT `done` AND `pid` != 0'],
 559                         ['order' => ['priority', 'created']]
 560                 );
 561                 self::$db_duration += (microtime(true) - $stamp);
 562
 563                 while ($entry = DBA::fetch($entries)) {
 564                         if (!posix_kill($entry["pid"], 0)) {
 565                                 $stamp = (float)microtime(true);
 566                                 DBA::update(
 567                                         'workerqueue',
 568                                         ['executed' => DBA::NULL_DATETIME, 'pid' => 0],
 569                                         ['id' => $entry["id"]]
 570                                 );
 571                                 self::$db_duration += (microtime(true) - $stamp);
 572                                 self::$db_duration_write += (microtime(true) - $stamp);
 573                         } else {
 574                                 // Kill long running processes
 575                                 // Check if the priority is in a valid range
 576                                 if (!in_array($entry["priority"], [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE])) {
 577                                         $entry["priority"] = PRIORITY_MEDIUM;
 578                                 }
 579
 580                                 // Define the maximum durations
 581                                 $max_duration_defaults = [PRIORITY_CRITICAL => 720, PRIORITY_HIGH => 10, PRIORITY_MEDIUM => 60, PRIORITY_LOW => 180, PRIORITY_NEGLIGIBLE => 720];
 582                                 $max_duration = $max_duration_defaults[$entry["priority"]];
 583
 584                                 $argv = json_decode($entry["parameter"], true);
 585                                 $argv[0] = basename($argv[0]);
 586
 587                                 // How long is the process already running?
 588                                 $duration = (time() - strtotime($entry["executed"])) / 60;
 589                                 if ($duration > $max_duration) {
 590                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") took more than ".$max_duration." minutes. It will be killed now.");
 591                                         posix_kill($entry["pid"], SIGTERM);
 592
 593                                         // We killed the stale process.
 594                                         // To avoid a blocking situation we reschedule the process at the beginning of the queue.
 595                                         // Additionally we are lowering the priority. (But not PRIORITY_CRITICAL)
 596                                         $new_priority = $entry["priority"];
 597                                         if ($entry["priority"] == PRIORITY_HIGH) {
 598                                                 $new_priority = PRIORITY_MEDIUM;
 599                                         } elseif ($entry["priority"] == PRIORITY_MEDIUM) {
 600                                                 $new_priority = PRIORITY_LOW;
 601                                         } elseif ($entry["priority"] != PRIORITY_CRITICAL) {
 602                                                 $new_priority = PRIORITY_NEGLIGIBLE;
 603                                         }
 604                                         $stamp = (float)microtime(true);
 605                                         DBA::update(
 606                                                 'workerqueue',
 607                                                 ['executed' => DBA::NULL_DATETIME, 'created' => DateTimeFormat::utcNow(), 'priority' => $new_priority, 'pid' => 0],
 608                                                 ['id' => $entry["id"]]
 609                                         );
 610                                         self::$db_duration += (microtime(true) - $stamp);
 611                                         self::$db_duration_write += (microtime(true) - $stamp);
 612                                 } else {
 613                                         Logger::log("Worker process ".$entry["pid"]." (".substr(json_encode($argv), 0, 50).") now runs for ".round($duration)." of ".$max_duration." allowed minutes. That's okay.", Logger::DEBUG);
 614                                 }
 615                         }
 616                 }
 617         }
 618
 619         /**
 620          * Checks if the number of active workers exceeds the given limits
 621          *
 622          * @return bool Are there too much workers running?
 623          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 624          */
 625         private static function tooMuchWorkers()
 626         {
 627                 $queues = DI::config()->get("system", "worker_queues", 10);
 628
 629                 $maxqueues = $queues;
 630
 631                 $active = self::activeWorkers();
 632
 633                 // Decrease the number of workers at higher load
 634                 $load = System::currentLoad();
 635                 if ($load) {
 636                         $maxsysload = intval(DI::config()->get("system", "maxloadavg", 20));
 637
 638                         /* Default exponent 3 causes queues to rapidly decrease as load increases.
 639                          * If you have 20 max queues at idle, then you get only 5 queues at 37.1% of $maxsysload.
 640                          * For some environments, this rapid decrease is not needed.
 641                          * With exponent 1, you could have 20 max queues at idle and 13 at 37% of $maxsysload.
 642                          */
 643                         $exponent = intval(DI::config()->get('system', 'worker_load_exponent', 3));
 644                         $slope = pow(max(0, $maxsysload - $load) / $maxsysload, $exponent);
 645                         $queues = intval(ceil($slope * $maxqueues));
 646
 647                         $processlist = '';
 648
 649                         if (DI::config()->get('system', 'worker_jpm')) {
 650                                 $intervals = explode(',', DI::config()->get('system', 'worker_jpm_range'));
 651                                 $jobs_per_minute = [];
 652                                 foreach ($intervals as $interval) {
 653                                         if ($interval == 0) {
 654                                                 continue;
 655                                         } else {
 656                                                 $interval = (int)$interval;
 657                                         }
 658
 659                                         $stamp = (float)microtime(true);
 660                                         $jobs = DBA::p("SELECT COUNT(*) AS `jobs` FROM `workerqueue` WHERE `done` AND `executed` > UTC_TIMESTAMP() - INTERVAL ? MINUTE", $interval);
 661                                         self::$db_duration += (microtime(true) - $stamp);
 662                                         self::$db_duration_stat += (microtime(true) - $stamp);
 663                                         if ($job = DBA::fetch($jobs)) {
 664                                                 $jobs_per_minute[$interval] = number_format($job['jobs'] / $interval, 0);
 665                                         }
 666                                         DBA::close($jobs);
 667                                 }
 668                                 $processlist = ' - jpm: '.implode('/', $jobs_per_minute);
 669                         }
 670
 671                         // Create a list of queue entries grouped by their priority
 672                         $listitem = [0 => ''];
 673
 674                         $idle_workers = $active;
 675
 676                         $deferred = self::deferredEntries();
 677
 678                         if (DI::config()->get('system', 'worker_debug')) {
 679                                 $waiting_processes = 0;
 680                                 // Now adding all processes with workerqueue entries
 681                                 $stamp = (float)microtime(true);
 682                                 $jobs = DBA::p("SELECT COUNT(*) AS `entries`, `priority` FROM `workerqueue` WHERE NOT `done` GROUP BY `priority`");
 683                                 self::$db_duration += (microtime(true) - $stamp);
 684                                 self::$db_duration_stat += (microtime(true) - $stamp);
 685                                 while ($entry = DBA::fetch($jobs)) {
 686                                         $stamp = (float)microtime(true);
 687                                         $processes = DBA::p("SELECT COUNT(*) AS `running` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` WHERE NOT `done` AND `priority` = ?", $entry["priority"]);
 688                                         self::$db_duration += (microtime(true) - $stamp);
 689                                         self::$db_duration_stat += (microtime(true) - $stamp);
 690                                         if ($process = DBA::fetch($processes)) {
 691                                                 $idle_workers -= $process["running"];
 692                                                 $waiting_processes += $entry["entries"];
 693                                                 $listitem[$entry["priority"]] = $entry["priority"].":".$process["running"]."/".$entry["entries"];
 694                                         }
 695                                         DBA::close($processes);
 696                                 }
 697                                 DBA::close($jobs);
 698                         } else {
 699                                 $waiting_processes =  self::totalEntries();
 700                                 $stamp = (float)microtime(true);
 701                                 $jobs = DBA::p("SELECT COUNT(*) AS `running`, `priority` FROM `process` INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid` AND NOT `done` GROUP BY `priority` ORDER BY `priority`");
 702                                 self::$db_duration += (microtime(true) - $stamp);
 703                                 self::$db_duration_stat += (microtime(true) - $stamp);
 704
 705                                 while ($entry = DBA::fetch($jobs)) {
 706                                         $idle_workers -= $entry["running"];
 707                                         $listitem[$entry["priority"]] = $entry["priority"].":".$entry["running"];
 708                                 }
 709                                 DBA::close($jobs);
 710                         }
 711
 712                         $waiting_processes -= $deferred;
 713
 714                         $listitem[0] = "0:" . max(0, $idle_workers);
 715
 716                         $processlist .= ' ('.implode(', ', $listitem).')';
 717
 718                         if (DI::config()->get("system", "worker_fastlane", false) && ($queues > 0) && ($active >= $queues) && self::entriesExists()) {
 719                                 $top_priority = self::highestPriority();
 720                                 $high_running = self::processWithPriorityActive($top_priority);
 721
 722                                 if (!$high_running && ($top_priority > PRIORITY_UNDEFINED) && ($top_priority < PRIORITY_NEGLIGIBLE)) {
 723                                         Logger::log("There are jobs with priority ".$top_priority." waiting but none is executed. Open a fastlane.", Logger::DEBUG);
 724                                         $queues = $active + 1;
 725                                 }
 726                         }
 727
 728                         Logger::log("Load: " . $load ."/" . $maxsysload . " - processes: " . $deferred . "/" . $active . "/" . $waiting_processes . $processlist . " - maximum: " . $queues . "/" . $maxqueues, Logger::DEBUG);
 729
 730                         // Are there fewer workers running as possible? Then fork a new one.
 731                         if (!DI::config()->get("system", "worker_dont_fork", false) && ($queues > ($active + 1)) && self::entriesExists()) {
 732                                 Logger::log("Active workers: ".$active."/".$queues." Fork a new worker.", Logger::DEBUG);
 733                                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
 734                                         self::IPCSetJobState(true);
 735                                 } else {
 736                                         self::spawnWorker();
 737                                 }
 738                         }
 739                 }
 740
 741                 // if there are too much worker, we don't spawn a new one.
 742                 if (DI::config()->get('system', 'worker_daemon_mode', false) && ($active > $queues)) {
 743                         self::IPCSetJobState(false);
 744                 }
 745
 746                 return $active > $queues;
 747         }
 748
 749         /**
 750          * Returns the number of active worker processes
 751          *
 752          * @return integer Number of active worker processes
 753          * @throws \Exception
 754          */
 755         private static function activeWorkers()
 756         {
 757                 $stamp = (float)microtime(true);
 758                 $count = DBA::count('process', ['command' => 'Worker.php']);
 759                 self::$db_duration += (microtime(true) - $stamp);
 760                 return $count;
 761         }
 762
 763         /**
 764          * Returns waiting jobs for the current process id
 765          *
 766          * @return array waiting workerqueue jobs
 767          * @throws \Exception
 768          */
 769         private static function getWaitingJobForPID()
 770         {
 771                 $stamp = (float)microtime(true);
 772                 $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 773                 self::$db_duration += (microtime(true) - $stamp);
 774                 if (DBA::isResult($r)) {
 775                         return DBA::toArray($r);
 776                 }
 777                 DBA::close($r);
 778
 779                 return false;
 780         }
 781
 782         /**
 783          * Returns the next jobs that should be executed
 784          *
 785          * @return array array with next jobs
 786          * @throws \Exception
 787          */
 788         private static function nextProcess()
 789         {
 790                 $priority = self::nextPriority();
 791                 if (empty($priority)) {
 792                         Logger::info('No tasks found');
 793                         return [];
 794                 }
 795
 796                 $limit = DI::config()->get('system', 'worker_fetch_limit', 1);
 797
 798                 $ids = [];
 799                 $stamp = (float)microtime(true);
 800                 $condition = ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()];
 801                 $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['created']]);
 802                 self::$db_duration += (microtime(true) - $stamp);
 803                 while ($task = DBA::fetch($tasks)) {
 804                         $ids[] = $task['id'];
 805                         // Only continue that loop while we are storing commands that can be processed quickly
 806                         $command = json_decode($task['parameter'])[0];
 807                         if (!in_array($command, self::FAST_COMMANDS)) {
 808                                 break;
 809                         }
 810                 }
 811                 DBA::close($tasks);
 812
 813                 Logger::info('Found:', ['priority' => $priority, 'id' => $ids]);
 814                 return $ids;
 815         }
 816
 817         /**
 818          * Returns the priority of the next workerqueue job
 819          *
 820          * @return string priority
 821          * @throws \Exception
 822          */
 823         private static function nextPriority()
 824         {
 825                 $waiting = [];
 826                 $priorities = [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE];
 827                 foreach ($priorities as $priority) {
 828                         $stamp = (float)microtime(true);
 829                         if (DBA::exists('workerqueue', ["`priority` = ? AND `pid` = 0 AND NOT `done` AND `next_try` < ?", $priority, DateTimeFormat::utcNow()])) {
 830                                 $waiting[$priority] = true;
 831                         }
 832                         self::$db_duration += (microtime(true) - $stamp);
 833                 }
 834
 835                 if (!empty($waiting[PRIORITY_CRITICAL])) {
 836                         return PRIORITY_CRITICAL;
 837                 }
 838
 839                 $running = [];
 840                 $running_total = 0;
 841                 $stamp = (float)microtime(true);
 842                 $processes = DBA::p("SELECT COUNT(DISTINCT(`process`.`pid`)) AS `running`, `priority` FROM `process`
 843                         INNER JOIN `workerqueue` ON `workerqueue`.`pid` = `process`.`pid`
 844                         WHERE NOT `done` GROUP BY `priority`");
 845                 self::$db_duration += (microtime(true) - $stamp);
 846                 while ($process = DBA::fetch($processes)) {
 847                         $running[$process['priority']] = $process['running'];
 848                         $running_total += $process['running'];
 849                 }
 850                 DBA::close($processes);
 851
 852                 foreach ($priorities as $priority) {
 853                         if (!empty($waiting[$priority]) && empty($running[$priority])) {
 854                                 Logger::info('No running worker found with priority {priority} - assigning it.', ['priority' => $priority]);
 855                                 return $priority;
 856                         }
 857                 }
 858
 859                 $active = max(self::activeWorkers(), $running_total);
 860                 $priorities = max(count($waiting), count($running));
 861                 $exponent = 2;
 862
 863                 $total = 0;
 864                 for ($i = 1; $i <= $priorities; ++$i) {
 865                         $total += pow($i, $exponent);
 866                 }
 867
 868                 $limit = [];
 869                 for ($i = 1; $i <= $priorities; ++$i) {
 870                         $limit[$priorities - $i] = max(1, round($active * (pow($i, $exponent) / $total)));
 871                 }
 872
 873                 $i = 0;
 874                 foreach ($running as $priority => $workers) {
 875                         if ($workers < $limit[$i++]) {
 876                                 Logger::info('Priority {priority} has got {workers} workers out of a limit of {limit}', ['priority' => $priority, 'workers' => $workers, 'limit' => $limit[$i - 1]]);
 877                                 return $priority;
 878                         }
 879                 }
 880
 881                 if (!empty($waiting)) {
 882                         $priority = array_keys($waiting)[0];
 883                         Logger::info('No underassigned priority found, now taking the highest priority.', ['priority' => $priority]);
 884                         return $priority;
 885                 }
 886
 887                 return false;
 888         }
 889
 890         /**
 891          * Find and claim the next worker process for us
 892          *
 893          * @return boolean Have we found something?
 894          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 895          */
 896         private static function findWorkerProcesses()
 897         {
 898                 $mypid = getmypid();
 899
 900                 $ids = self::nextProcess();
 901
 902                 // If there is no result we check without priority limit
 903                 if (empty($ids)) {
 904                         $limit = DI::config()->get('system', 'worker_fetch_limit', 1);
 905
 906                         $stamp = (float)microtime(true);
 907                         $condition = ["`pid` = 0 AND NOT `done` AND `next_try` < ?", DateTimeFormat::utcNow()];
 908                         $tasks = DBA::select('workerqueue', ['id', 'parameter'], $condition, ['limit' => $limit, 'order' => ['priority', 'created']]);
 909                         self::$db_duration += (microtime(true) - $stamp);
 910
 911                         while ($task = DBA::fetch($tasks)) {
 912                                 $ids[] = $task['id'];
 913                                 // Only continue that loop while we are storing commands that can be processed quickly
 914                                 $command = json_decode($task['parameter'])[0];
 915                                 if (!in_array($command, self::FAST_COMMANDS)) {
 916                                         break;
 917                                 }
 918                         }
 919                         DBA::close($tasks);
 920                 }
 921
 922                 if (!empty($ids)) {
 923                         $stamp = (float)microtime(true);
 924                         $condition = ['id' => $ids, 'done' => false, 'pid' => 0];
 925                         DBA::update('workerqueue', ['executed' => DateTimeFormat::utcNow(), 'pid' => $mypid], $condition);
 926                         self::$db_duration += (microtime(true) - $stamp);
 927                         self::$db_duration_write += (microtime(true) - $stamp);
 928                 }
 929
 930                 return !empty($ids);
 931         }
 932
 933         /**
 934          * Returns the next worker process
 935          *
 936          * @return string SQL statement
 937          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 938          */
 939         public static function workerProcess()
 940         {
 941                 // There can already be jobs for us in the queue.
 942                 $waiting = self::getWaitingJobForPID();
 943                 if (!empty($waiting)) {
 944                         return $waiting;
 945                 }
 946
 947                 $stamp = (float)microtime(true);
 948                 if (!DI::lock()->acquire('worker_process')) {
 949                         return false;
 950                 }
 951                 self::$lock_duration += (microtime(true) - $stamp);
 952
 953                 $found = self::findWorkerProcesses();
 954
 955                 DI::lock()->release('worker_process');
 956
 957                 if ($found) {
 958                         $stamp = (float)microtime(true);
 959                         $r = DBA::select('workerqueue', [], ['pid' => getmypid(), 'done' => false]);
 960                         self::$db_duration += (microtime(true) - $stamp);
 961                         return DBA::toArray($r);
 962                 }
 963                 return false;
 964         }
 965
 966         /**
 967          * Removes a workerqueue entry from the current process
 968          *
 969          * @return void
 970          * @throws \Exception
 971          */
 972         public static function unclaimProcess()
 973         {
 974                 $mypid = getmypid();
 975
 976                 $stamp = (float)microtime(true);
 977                 DBA::update('workerqueue', ['executed' => DBA::NULL_DATETIME, 'pid' => 0], ['pid' => $mypid, 'done' => false]);
 978                 self::$db_duration += (microtime(true) - $stamp);
 979                 self::$db_duration_write += (microtime(true) - $stamp);
 980         }
 981
 982         /**
 983          * Call the front end worker
 984          *
 985          * @return void
 986          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 987          */
 988         public static function callWorker()
 989         {
 990                 if (!DI::config()->get("system", "frontend_worker")) {
 991                         return;
 992                 }
 993
 994                 $url = DI::baseUrl() . '/worker';
 995                 Network::fetchUrl($url, false, 1);
 996         }
 997
 998         /**
 999          * Call the front end worker if there aren't any active
1000          *
1001          * @return void
1002          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1003          */
1004         public static function executeIfIdle()
1005         {
1006                 if (!DI::config()->get("system", "frontend_worker")) {
1007                         return;
1008                 }
1009
1010                 // Do we have "proc_open"? Then we can fork the worker
1011                 if (function_exists("proc_open")) {
1012                         // When was the last time that we called the worker?
1013                         // Less than one minute? Then we quit
1014                         if ((time() - DI::config()->get("system", "worker_started")) < 60) {
1015                                 return;
1016                         }
1017
1018                         DI::config()->set("system", "worker_started", time());
1019
1020                         // Do we have enough running workers? Then we quit here.
1021                         if (self::tooMuchWorkers()) {
1022                                 // Cleaning dead processes
1023                                 self::killStaleWorkers();
1024                                 Process::deleteInactive();
1025
1026                                 return;
1027                         }
1028
1029                         self::runCron();
1030
1031                         Logger::log('Call worker', Logger::DEBUG);
1032                         self::spawnWorker();
1033                         return;
1034                 }
1035
1036                 // We cannot execute background processes.
1037                 // We now run the processes from the frontend.
1038                 // This won't work with long running processes.
1039                 self::runCron();
1040
1041                 self::clearProcesses();
1042
1043                 $workers = self::activeWorkers();
1044
1045                 if ($workers == 0) {
1046                         self::callWorker();
1047                 }
1048         }
1049
1050         /**
1051          * Removes long running worker processes
1052          *
1053          * @return void
1054          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1055          */
1056         public static function clearProcesses()
1057         {
1058                 $timeout = DI::config()->get("system", "frontend_worker_timeout", 10);
1059
1060                 /// @todo We should clean up the corresponding workerqueue entries as well
1061                 $stamp = (float)microtime(true);
1062                 $condition = ["`created` < ? AND `command` = 'worker.php'",
1063                                 DateTimeFormat::utc("now - ".$timeout." minutes")];
1064                 DBA::delete('process', $condition);
1065                 self::$db_duration = (microtime(true) - $stamp);
1066                 self::$db_duration_write += (microtime(true) - $stamp);
1067         }
1068
1069         /**
1070          * Runs the cron processes
1071          *
1072          * @return void
1073          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1074          */
1075         private static function runCron()
1076         {
1077                 Logger::log('Add cron entries', Logger::DEBUG);
1078
1079                 // Check for spooled items
1080                 self::add(['priority' => PRIORITY_HIGH, 'force_priority' => true], 'SpoolPost');
1081
1082                 // Run the cron job that calls all other jobs
1083                 self::add(['priority' => PRIORITY_MEDIUM, 'force_priority' => true], 'Cron');
1084
1085                 // Cleaning dead processes
1086                 self::killStaleWorkers();
1087         }
1088
1089         /**
1090          * Spawns a new worker
1091          *
1092          * @param bool $do_cron
1093          * @return void
1094          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1095          */
1096         public static function spawnWorker($do_cron = false)
1097         {
1098                 $command = 'bin/worker.php';
1099
1100                 $args = ['no_cron' => !$do_cron];
1101
1102                 $a = DI::app();
1103                 $process = new Core\Process(DI::logger(), DI::mode(), DI::config(), $a->getBasePath());
1104                 $process->run($command, $args);
1105
1106                 // after spawning we have to remove the flag.
1107                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
1108                         self::IPCSetJobState(false);
1109                 }
1110         }
1111
1112         /**
1113          * Adds tasks to the worker queue
1114          *
1115          * @param (integer|array) priority or parameter array, strings are deprecated and are ignored
1116          *
1117          * next args are passed as $cmd command line
1118          * or: Worker::add(PRIORITY_HIGH, "Notifier", Delivery::DELETION, $drop_id);
1119          * or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
1120          *
1121          * @return boolean "false" if worker queue entry already existed or there had been an error
1122          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1123          * @note $cmd and string args are surrounded with ""
1124          *
1125          * @hooks 'proc_run'
1126          *    array $arr
1127          *
1128          */
1129         public static function add($cmd)
1130         {
1131                 $args = func_get_args();
1132
1133                 if (!count($args)) {
1134                         return false;
1135                 }
1136
1137                 $arr = ['args' => $args, 'run_cmd' => true];
1138
1139                 Hook::callAll("proc_run", $arr);
1140                 if (!$arr['run_cmd'] || !count($args)) {
1141                         return true;
1142                 }
1143
1144                 $priority = PRIORITY_MEDIUM;
1145                 // Don't fork from frontend tasks by default
1146                 $dont_fork = DI::config()->get("system", "worker_dont_fork", false) || !DI::mode()->isBackend();
1147                 $created = DateTimeFormat::utcNow();
1148                 $force_priority = false;
1149
1150                 $run_parameter = array_shift($args);
1151
1152                 if (is_int($run_parameter)) {
1153                         $priority = $run_parameter;
1154                 } elseif (is_array($run_parameter)) {
1155                         if (isset($run_parameter['priority'])) {
1156                                 $priority = $run_parameter['priority'];
1157                         }
1158                         if (isset($run_parameter['created'])) {
1159                                 $created = $run_parameter['created'];
1160                         }
1161                         if (isset($run_parameter['dont_fork'])) {
1162                                 $dont_fork = $run_parameter['dont_fork'];
1163                         }
1164                         if (isset($run_parameter['force_priority'])) {
1165                                 $force_priority = $run_parameter['force_priority'];
1166                         }
1167                 }
1168
1169                 $parameters = json_encode($args);
1170                 $found = DBA::exists('workerqueue', ['parameter' => $parameters, 'done' => false]);
1171                 $added = false;
1172
1173                 // Quit if there was a database error - a precaution for the update process to 3.5.3
1174                 if (DBA::errorNo() != 0) {
1175                         return false;
1176                 }
1177
1178                 if (!$found) {
1179                         $added = DBA::insert('workerqueue', ['parameter' => $parameters, 'created' => $created, 'priority' => $priority]);
1180                         if (!$added) {
1181                                 return false;
1182                         }
1183                 } elseif ($force_priority) {
1184                         DBA::update('workerqueue', ['priority' => $priority], ['parameter' => $parameters, 'done' => false, 'pid' => 0]);
1185                 }
1186
1187                 // Should we quit and wait for the worker to be called as a cronjob?
1188                 if ($dont_fork) {
1189                         return $added;
1190                 }
1191
1192                 // If there is a lock then we don't have to check for too much worker
1193                 if (!DI::lock()->acquire('worker', 0)) {
1194                         return $added;
1195                 }
1196
1197                 // If there are already enough workers running, don't fork another one
1198                 $quit = self::tooMuchWorkers();
1199                 DI::lock()->release('worker');
1200
1201                 if ($quit) {
1202                         return $added;
1203                 }
1204
1205                 // We tell the daemon that a new job entry exists
1206                 if (DI::config()->get('system', 'worker_daemon_mode', false)) {
1207                         // We don't have to set the IPC flag - this is done in "tooMuchWorkers"
1208                         return $added;
1209                 }
1210
1211                 // Now call the worker to execute the jobs that we just added to the queue
1212                 self::spawnWorker();
1213
1214                 return $added;
1215         }
1216
1217         /**
1218          * Returns the next retrial level for worker jobs.
1219          * This function will skip levels when jobs are older.
1220          *
1221          * @param array $queue Worker queue entry
1222          * @param integer $max_level maximum retrial level
1223          * @return integer the next retrial level value
1224          */
1225         private static function getNextRetrial($queue, $max_level)
1226         {
1227                 $created = strtotime($queue['created']);
1228                 $retrial_time = time() - $created;
1229
1230                 $new_retrial = $queue['retrial'] + 1;
1231                 $total = 0;
1232                 for ($retrial = 0; $retrial <= $max_level + 1; ++$retrial) {
1233                         $delay = (($retrial + 3) ** 4) + (rand(1, 30) * ($retrial + 1));
1234                         $total += $delay;
1235                         if (($total < $retrial_time) && ($retrial > $queue['retrial'])) {
1236                                 $new_retrial = $retrial;
1237                         }
1238                 }
1239                 Logger::info('New retrial for task', ['id' => $queue['id'], 'created' => $queue['created'], 'old' => $queue['retrial'], 'new' => $new_retrial]);
1240                 return $new_retrial;
1241         }
1242
1243         /**
1244          * Defers the current worker entry
1245          *
1246          * @return boolean had the entry been deferred?
1247          */
1248         public static function defer()
1249         {
1250                 if (empty(DI::app()->queue)) {
1251                         return false;
1252                 }
1253
1254                 $queue = DI::app()->queue;
1255
1256                 $retrial = $queue['retrial'];
1257                 $id = $queue['id'];
1258                 $priority = $queue['priority'];
1259
1260                 $max_level = DI::config()->get('system', 'worker_defer_limit');
1261
1262                 $new_retrial = self::getNextRetrial($queue, $max_level);
1263
1264                 if ($new_retrial > $max_level) {
1265                         Logger::info('The task exceeded the maximum retry count', ['id' => $id, 'created' => $queue['created'], 'old_prio' => $queue['priority'], 'old_retrial' => $queue['retrial'], 'max_level' => $max_level, 'retrial' => $new_retrial]);
1266                         return false;
1267                 }
1268
1269                 // Calculate the delay until the next trial
1270                 $delay = (($new_retrial + 2) ** 4) + (rand(1, 30) * ($new_retrial));
1271                 $next = DateTimeFormat::utc('now + ' . $delay . ' seconds');
1272
1273                 if (($priority < PRIORITY_MEDIUM) && ($new_retrial > 3)) {
1274                         $priority = PRIORITY_MEDIUM;
1275                 } elseif (($priority < PRIORITY_LOW) && ($new_retrial > 6)) {
1276                         $priority = PRIORITY_LOW;
1277                 } elseif (($priority < PRIORITY_NEGLIGIBLE) && ($new_retrial > 8)) {
1278                         $priority = PRIORITY_NEGLIGIBLE;
1279                 }
1280
1281                 Logger::info('Deferred task', ['id' => $id, 'retrial' => $new_retrial, 'created' => $queue['created'], 'next_execution' => $next, 'old_prio' => $queue['priority'], 'new_prio' => $priority]);
1282
1283                 $stamp = (float)microtime(true);
1284                 $fields = ['retrial' => $new_retrial, 'next_try' => $next, 'executed' => DBA::NULL_DATETIME, 'pid' => 0, 'priority' => $priority];
1285                 DBA::update('workerqueue', $fields, ['id' => $id]);
1286                 self::$db_duration += (microtime(true) - $stamp);
1287                 self::$db_duration_write += (microtime(true) - $stamp);
1288
1289                 return true;
1290         }
1291
1292         /**
1293          * Log active processes into the "process" table
1294          */
1295         public static function startProcess()
1296         {
1297                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
1298
1299                 $command = basename($trace[0]['file']);
1300
1301                 Process::deleteInactive();
1302
1303                 Process::insert($command);
1304         }
1305
1306         /**
1307          * Remove the active process from the "process" table
1308          *
1309          * @return bool
1310          * @throws \Exception
1311          */
1312         public static function endProcess()
1313         {
1314                 return Process::deleteByPid();
1315         }
1316
1317         /**
1318          * Set the flag if some job is waiting
1319          *
1320          * @param boolean $jobs Is there a waiting job?
1321          * @throws \Exception
1322          */
1323         public static function IPCSetJobState($jobs)
1324         {
1325                 $stamp = (float)microtime(true);
1326                 DBA::update('worker-ipc', ['jobs' => $jobs], ['key' => 1], true);
1327                 self::$db_duration += (microtime(true) - $stamp);
1328                 self::$db_duration_write += (microtime(true) - $stamp);
1329         }
1330
1331         /**
1332          * Checks if some worker job waits to be executed
1333          *
1334          * @return bool
1335          * @throws \Exception
1336          */
1337         public static function IPCJobsExists()
1338         {
1339                 $stamp = (float)microtime(true);
1340                 $row = DBA::selectFirst('worker-ipc', ['jobs'], ['key' => 1]);
1341                 self::$db_duration += (microtime(true) - $stamp);
1342
1343                 // When we don't have a row, no job is running
1344                 if (!DBA::isResult($row)) {
1345                         return false;
1346                 }
1347
1348                 return (bool)$row['jobs'];
1349         }
1350 }